She later earned her Masters degree and her doctorate in English, with an emphasis on cinema studies, women's literature, and popular culture, and now teaches courses specializing in film, class, race and gender studies, as well as eco-critical approaches to film and popular culture.

Her many booksinclude such titles as A Short History of Film (Rutgers University Press, co-written with Wheeler Winston Dixon, second edition 2013; third edition 2018); Class-Passing: Social Mobility in Film and Popular Culture (Southern Illinois University Press, 2005); Performing Whiteness: Postmodern Re/Constructions (State University of New York Press, 2003); and Identity and Memory: The Films of Chantal Akerman (Southern Illinois University Press, 2003).

Her other works include Experimental Cinema: The Film Reader (co-edited with Wheeler Winston Dixon, Routledge, 2002); Troping the Body: Etiquette, Conduct and Dialogic Performance (Southern Illinois University Press, 2000) and Captive Bodies: Postcolonialism in the Cinema (State University of New York Press, 1999). Foster's book Performing Whiteness: Postmodern Re/Constructions was cited by the journal Choice as "Essential . . . one of the Outstanding Academic Books of the Year."

In 2015, Foster and Dixon inaugurated the Quick Takes: Movies and Popular Culture for Rutgers University Press, a new series of books on film and popular culture. To date, twenty books have been contracted for the series, featuring such key authors as Steven Shaviro, David Sterritt, Valérie Orlando, Blair Davis and many others.

Foster teaches a broad variety of courses that reflect her diverse interests: Ozu and Asian Cinema, Bresson and French Cinema, Spanish and Mexican cinema, The Films of Luis Buñuel, Experimental filmmakers, Pre-Code Cinema and Film Censorship, Women Filmmakers in History, Feminist and Marxist Approaches to Film Theory, Apoco-tainment, Eco-Horror and Environmentalism in TV and Film, The Woman's Picture and Melodrama, Female Spectatorship, Race and Postcolonialism in Film, Queer Theory, Feminist Film Theory, Gay and Lesbian Filmmakers, Masculinity in Film and Media, and many other courses.

Her documentary film,Women Who Made The Movies,is distributed by Women Make Movies, New York, and has become a classic in the field of feminist cinema history.